This is a 10,000-year rabbit hole!
The Waste Isolation Pilot Plant (WIPP) was designed to store radioactive waste in Nevada. The storage area would not be safe to enter until 10,000 years had passed. Several groups of smart people came together to design warning messages that could outlive our civilization and protect future explorers. These designers knew they couldn't rely on any current language surviving that long, so they worked on landscape designs that project "this is toxic waste, don't mess!" Listen to the 99% Invisible podcast episode (or read the transcript there) for the current state of the WIPP, and the design process for the warning symbols:
I learned about the WIPP through several Metafilter posts. One of the discussions mentioned Yuletide, and wow there are some fascinating fanfics on the topic.
The Green Cats of Desolation City by Serenade http://archiveofourown.org/works/8887861 Languages change, inscriptions fade, but cats are forever. As the 99PI podcast explains, this solution came through unofficial channels.
The One and the Many by Clocketpatch http://archiveofourown.org/works/8796376 Excellent far future SF story. Outworlders come back to Earth, pair up with human-descended ambassadors, and try to dig through a mass of culture conflict and desert rock.
The Long View and the Short by AstroGirl http://archiveofourown.org/works/8803036 Well-written and sad, this story pinballs between various "now"s and how the people of those times interact with the WIPP.
Pyramid Schemes by primeideal http://archiveofourown.org/works/5475131 In true Yuletide tradition, it's a 5 + 1 fic, exploring how a Linda and a Jo couple up near the WIPP, with five levels of failure and one success.
One of the forbidding-landscape proposals is incorporated into California, a meh dystopian novel published by a non-genre writer in 2014. If the WIPP project follows up on the experts' suggestions, elements of those proposal should be showing up in pop culture for millennia.
The WIPP-fic tag: